Home Battery Subsidies in Luxembourg

What the support covers under the Klimabonus Wunnen

The Klimabonus Wunnen, which replaced the former PRIMe House programme in 2022, includes a dedicated strand for home storage batteries coupled to a photovoltaic installation. The support targets the storage equipment itself and the integration works needed to connect it, not the photovoltaic installation as such, which falls under a separate strand of the same scheme.

This battery strand is designed to support self-consumption: a battery stores electricity produced during the day so it can be used in the evening, reducing the share of electricity bought from the grid. The support recognises this role without replacing the profitability calculation that each household must make based on its own consumption profile.

The eligibility logic

Three conditions generally structure eligibility. First, the battery must be coupled to a photovoltaic installation, whether existing or installed at the same time; a stand-alone battery without associated solar generation does not fall under this strand. Second, the works must be carried out by a company authorised to perform the relevant activity in Luxembourg, which rules out self-installation or an unauthorised installer. Third, the installation must be located in a dwelling within the meaning of the scheme, which in principle excludes purely professional uses or non-residential buildings.

These three conditions should be checked before signing the quote, since an installation that does not meet them cannot qualify for support even if it is technically sound.

Documents typically required

An application file typically gathers proof of ownership or occupancy of the dwelling, the company's detailed quote describing the battery's capacity and its integration with the photovoltaic installation, proof of the company's establishment authorisation, and, once the works are complete, the settled invoice and possibly a commissioning certificate.

The exact list and forms to use are those published by the administration at the time of application; it is best to obtain them directly when applying rather than relying on an older list, as the required documents can change.

The order of the procedure

It is useful to start with free, independent advice from Klima-Agence to check the project's consistency before any financial commitment. Next comes the detailed quote from the chosen company, which forms the basis of the subsidy application.

Depending on the scheme in force at the time of the project, the application may need to be submitted before works begin: this must be checked before signing an order or letting the site start, otherwise the subsidy may be lost for works already under way. After completion, settled invoices complete the file, which is then reviewed by the relevant administration.

Combining with the photovoltaic subsidy

In principle, the battery strand can be combined with the photovoltaic strand of the Klimabonus Wunnen when both installations are carried out together or when the battery complements an existing solar installation. Each strand nonetheless follows its own calculation logic and its own caps, and both files must be prepared separately even when they relate to the same site.

The exact amounts, caps and combination rules change over time and are set by the administration: they should not be inferred from an estimate found on a commercial website but checked on the official page at the time of the application.

Common reasons a file is rejected

A file is often rejected or sent back for completion when the application was submitted after works had already started although the scheme required it beforehand, when the company that carried out the installation lacks the required establishment authorisation, when the battery is not coupled to a photovoltaic installation, or when supporting documents are missing or incomplete, such as an invoice that does not sufficiently detail the equipment installed.

Checking each of these points before signing the quote avoids most refusals; when in doubt, Klima-Agence can confirm whether a specific project meets the conditions in force.

Where to get the exact amounts and free advice

The subsidy amounts, caps and eligibility conditions applicable at the time of your application are published on the official guichet.lu website, the only source to consult for a binding figure. Klima-Agence also offers free, independent energy advice to assess a home battery project before any commitment.